Tom Becker was nice enough to email us and comment on our <a href="http://www.sparkfun.com/commerce/present.php?p=GPSClock-1">12ft. GPS wall clock</a>. Then he put us to shame...
Tom Becker was nice enough to email us and comment on our 12ft. GPS wall clock
Then he put us to shame...
- Solid State Relay
- 80A Surge
- Digital Control
- Doomed Tubes
- The Clock
From Tom: The clock was installed in a building in Miami from 1997 through 1999. Each digit was about six feet tall, 54" wide, and used twin 36" fluorescent tubes for each segment. Each segment used a special ballast, a 'flashing ballast'
(for the motel signs of earlier days that are rarely permitted today if it is visible from any highway) that kept the tube filaments warm continually. The high voltage arcs of each segment were switched with twin solid-state relays in series, and each segment was monitored with a photosensor that assured the digit was displaying the intended pattern; if any segment failure occurred, the clock went dark rather than display an incorrect time. The control software also kept statistics on each tube's start count, predicting failures so they could be changed out before a failure occurred. The most dynamic was one segment in the seconds LSD. Amazingly, each digit start could draw an 80A pulse for a few milliseconds, so software determined the best turn-on sequence to stagger digit starts across several AC line cycles so it could run from a single 20Amp 115VAC feed.
Well done Tom! Now for smaller bits.
It looks rather small next to Tom's displays, but is actually a red 1" tall 7-segment
common anode display.
Itty-bitty IR receiver. The TSOP85 module
from Vishay incorporates all the filtering and demodulation to make this a powerful little infrared device.
is now available on a spool to help LilyPad users get their projects integrated into their clothing.
That's a micro USB connector
. About half the height of a mini USB connector, micro USB was developed to allow cell phone manufacturers to create even slimmer hand-helds.
This is an RJ45 ethernet jack
with built-in transformer. Commonly called a 'MagJack' - we've got them for cheap!
The last piece of the 10-pin programming puzzle. We now stock the simple 10-pin IDC cable
commonly used for programming but with many other applications.
A small barrel jack
to adapt our wall warts is now available.